[PATCH v16 09/18] arm64: syscall: Rework the syscall exit path in el0_svc_common()

[Jinjie Ruan]

In preparation for moving arm64 over to the generic entry code,
restructure the fast-path syscall exit sequence within el0_svc_common().

Invert the nested conditional flags check so that when syscall work is
pending or single-stepping is active, the corresponding exit work can be
dispatched directly from within the fast-path bailout block. This clarifies
the separation between the fast and slow exit paths, facilitating a cleaner
transition to the generic entry state machine in subsequent patches.

No functional changes.

Cc: Mark Rutland <mark.rutland at arm.com>
Cc: Will Deacon <will at kernel.org>
Cc: Catalin Marinas <catalin.marinas at arm.com>
Cc: Ada Couprie Diaz <ada.coupriediaz at arm.com>
Signed-off-by: Jinjie Ruan <ruanjinjie at huawei.com>
---
 arch/arm64/kernel/syscall.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kernel/syscall.c b/arch/arm64/kernel/syscall.c
index 43ffb74162c5..f6e9aa132b09 100644
--- a/arch/arm64/kernel/syscall.c
+++ b/arch/arm64/kernel/syscall.c
@@ -127,8 +127,11 @@ static void el0_svc_common(struct pt_regs *regs, int scno, int sc_nr,
 	 */
 	if (!has_syscall_work(flags) && !IS_ENABLED(CONFIG_DEBUG_RSEQ)) {
 		flags = read_thread_flags();
-		if (!has_syscall_work(flags) && !(flags & _TIF_SINGLESTEP))
-			return;
+		if (has_syscall_work(flags) || flags & _TIF_SINGLESTEP) {
+			flags = read_thread_flags();
+			syscall_exit_work(regs, flags);
+		}
+		return;
 	}
 
 trace_exit:
-- 
2.34.1